1 Technical Field
The present invention relates to control apparatuses for switched reluctance motors which include a stator having a plurality of pairs of opposing salient poles, each pair of the opposing salient poles having a plurality of coils of the same phase wound thereon, and a rotor arranged so as to be rotatable relative to the stator.
2 Description of the Related Art
Japanese Patent No. 5050455 discloses a control apparatus for a SR (Switched Reluctance) motor. The SR motor includes a stator that has two pairs of opposing salient poles for each of three phases. Each of the salient poles has one coil wound thereon. Moreover, for each pair of the opposing salient poles, the two coils respectively wound on the opposing salient poles of the pair are of the same phase.
The control apparatus is configured to include a plurality of drive circuits (or hysteresis comparator circuits) each of which corresponds to one of the coils wound on the salient poles of the stator of the SR motor. Moreover, for each pair of the opposing salient poles of the stator, the phases of energizing and de-energizing operations of the drive circuit corresponding to one of the two coils respectively wound on the opposing salient poles of the pair are set different from those of energizing and de-energizing operations of the drive circuit corresponding to the other coil. Consequently, it is possible to reduce ripple of electric current flowing to a capacitor that is electrically connected in parallel with the coils wound on the salient poles of the stator.
However, with the above configuration, since the energizing and de-energizing operations of the drive circuits are alternately performed, the flux linkage waveforms of the coils may be distorted. In this case, the flux linkage waveforms of the coils contain many harmonics, thereby increasing the iron loss of the SR motor due to the harmonics.